Chapter Edit replaces .ifo files with new ones after adding or deleting chapters. With masscamp24's experience, there must be a bug in the program that alters the region code. I've tried this tool a few times for testing and so far never had this problem yet. Unfortunately, there is no new update for this program

You don't have to worry about that. VobEdit will do that for you automatically. For example, if you have a combined files which are over 1 GB, VobEdit will make 2 .vob files (one of 0.99 GB and the rest of the file belongs to the second .vob file)